For example cutting inserts find application with tools for the chip removal treatment of workpiece surfaces to be smoothing, such as by a cutterhead which can be rotated about an axis and which comprises several exchangeable cutting plates, having main cutting edges, wherein the cutting plates are arranged along its front surface in the area of its outer periphery, as well as a smoothing arrangement, wherein the lateral surface (axial outer surface) of each cutting plate facing away from the front surface of the cutterhead is inclined by a setting angle with respect to the cutterhead. Such cutterheads are used for the treatment of machine parts, in particular, such as motors. The rotational axis of the cutterhead is oriented essentially at a right angle to the workpiece surface to be treated. Slight deviations from a 90.degree. orientation may result from a purposely provided spindle drop, a tilt error of the spindle, as well as the torque between the cutterhead and the workpiece. For this reason and for reasons of measuring and due to location deviations of the cutting plates and of the cutting plate sites on the cutterhead, the workpiece which is merely treated with the cutting plates, has a surface which, for many applications, is still too rough. For this reason, the cutterheads are provided with a smoothing device. In the case of known cutterheads, the latter consists, as a rule, of a single so-called broad smoothing plate per cutterhead, which, for example, in the position of one of the cutting plates of the cutterhead is used in the place of this cutting plate. Its essentially radially extending cutting edge must be oriented very precisely in the parallel direction to the treated workpiece surface. Irregularities in the cutting edge, imprecise installation of the broad smoothing plate, as well as fluctuating loads on the cutterhead, as they may occur, for example, at the beginning or at the end of a workpiece surface to be cut, are immediately translated into a decline in the surface quality of the treated workpiece.
Furthermore, the requirements with respect to the surface quality of machine parts and the like subjected to chip removal, have increased. For example, sealing surfaces must have better surfaces when less elastic and/or asbestos-free seals are used. Another problem lies in the increasingly realized weight reductions which lead to comparatively thin-walled workpieces. Thin-walled workpieces increasingly tend towards bending under the cutting pressure during cutting, which can lead to a certain waviness of the treated workpiece surface.
Based on this, it is the task of the invention to construct a cutting insert (bit) and a tool of the initially mentioned type in such a way that high surface quality is achieved when comparatively long edge lives of the turnover cutting plates are involved. Also particularly desirable is as a gentle cutting of the cutterhead, i.e., a cutting involving as little cutting pressure as possible.